Island



D. H. coUcH Oct. 11,1927.

ROTARY DRIER 3 Sheets-Sheet 1 Filed March 25. 1926 Oct. 11, 1927.

H. cioUcH ROTARY DRIER i Fiec March 25. 1925 s sheets-sheet 2 va a Patented oci. 11, 1927.

unirse gs'ra'res miam rar-ENT caries,

DAVID H. COUCH, 0F WARWCK, RHODE ISLAND.

ROTARY DRIER.

Application led March 25, 1926. SerialNo. 97,316.

vide a type of drier which may be installed*l in any desired location without the necessity of having a furnace connected directly to the drier, thus making it possible to install the drier in locations where it would be impossible to locate it if an integral furnace were to be installed.

Also afurther object of my invention is to provide a drier of very large capacity suitable for drying coalk for large power plants using pulverized coal. f

Other objects will appear in the following specification and in the claims appended thereto. The preferred embodiment of my invention is'shownin thedrawings and consists of an outer shell, an inner shell preferably made up of helical grooves or corrugations forming one or more continuous threads from-one end of the shell to the other, the object of said threads or corrugations being to present a greater drying surface and provide a means foil rapidly moving the material thru the drier, and hollow. hubs connected to and communicating with the inner space between the shells by means of hollow spokes. These hollow hubs and spokes form the ports of entrance and discharge of the heating fluid which is forced thru the heating spaces between the inner and outer shells. As a heating medium, many kinds of liquids or even gases may be used, but for most purposes I prefer to use an oil of high flash point such as is sometimes used in industrial heating, this oil being heated by suitable external means and pumped thru the heating space between the shells. Any suitable liquids or even gases may be employed as heating fluids, but since a gas has a low specific heat and low density and since there would be a low transfer rate between a gas and the metal plates ofthe drier, heated liquids are preferable. In the following descriptionthe term liquid will be used'instead Lof the general term fluid The preferreddesign 0f Ymy invention is illustrated in the accompanying drawings wherein Fig. ll is a vertical longitudinal section I thru the centre of the drier.

Fig. 2 is an end elevation of a threegroove or flight drier.

Fig. Bjis a side elevation showing a general assembly of the drier and one system of heating and circulating the heating liquid.

Figs. t and 5 are vertical sections at right angles valve gear for causing the liquid to flow thru each channel in definite rotation, and

to one another of the liquid control Fig. 6'is a vertical longitudinal section of Y the revolving joint between the drier andV the stationary liquid supply piping. This revolving Joint is shown as a part of an elbow which forms a suitable anchorage for holding the shaft of the cam which operates the valves. It is not essential, however, that this member bein the forni of an elbow, but it may take any desired form.

Referring now in .detail to the several figures, the numeral l represents the outer shell of the drier which is preferably cylindrical and provided withk a ring gear 2 by `means of which the drier is rotated by a gear 3 on a suitably driven power shaft,v 4. Within the shell l, and preferably supported thereby, is aninner shell 5, having a spirally corrugated surface, the space between the outer shell and the helices of the inner shell forming a` chamber through which the heating liquid circulates. .Each helix forms a single spiral thread, continuing throughout the length of the shell forming a spiralpassage for the circulationv of the heating liquid.y In the present instance there are three parallel helices which open in the plane of the front of the drierv (the left-hand end in Figs. l and 3) as arcuate spaces 6, 7 and 8, each covering an angular distance of substantially 120 and being separated from one another by the partitions 9 representing the wall of the inner shell. The internal corrugations of the innei' shell serve .as flights for conveying the material to be dried from the forward to the discharge end of the drier, and also afford a large surface for. exposure of the material to the heating medium.

Heating liquid is supplied to the drierv from a suitable source, such as a boiler 40 connection consisting of a stationary elbow-- ion 11 and an axially arranged conduit 12 revolubly connected to said elbow in a manner presently to be explained. rlhe axial conduit 12 is in communication with a hollow hub 13 having radial distributing branches 14 leading each to one of the spi-ral passages 6, 7 or 8. The heating liquid leaves the drier through branch conduits 15 each communicating with one ot the spiral passages 6, 7 and 8 and with a hollow hub 16 with which the discharge conduit 1l' communicates, the latter being part ot a revolving joint `shown in detail in Figure 6. rlhis revolving joint comprises a fixed elbow 18 to which the discharge conduit 17 is swivelly connectedy by structure similar to that shown in connection. with the elbow 11. rlhis joint is preferably established by forming the ends of the conduit 17 and elbow 1S with .spherical portions 19 and 2O, respectively, one seated within the other as shown in Figure 6. A clamping ring 21 surrounds the spherical swell upon the stationary elbow and is formed with a spherical seat engaging said elbow. The clamping ring is held in resilient` engagement with the spherical swell on said fixed lelbow by means ot bolts Q2 passing,l through lianges on said ring and on the spherical: part of the conduit 17, said bolts vbeing provided with springs 23 normally heldin compression, and which draw the ring 21 and flange oit the spherical portion 19 together and thus urge the spherical seat portions 2.0i and 19 of the elbow 18 and con- '.cluit- 17 into fluid-tight engagement.

The present invention contemplates the supplyingv of heating lluid successively and in rotation to the three spiral passages, 'for which, purpose it isnecessary to have some kliorm of, valve control to. govern the admissionot theliquid. I have therefore devised .simple valve mechanism shown in detail in Fignred andwhichis perhaps most conveniently. located ufithinpthe hollow hub 16 at the discharge end of the drier. The branch conduits 15 are each provided with a valve closure 25ln'iounted on a stem 2b which passes through a transverse guide member 27 arranged in the. mouth of the conduit and also through a cylindrical guide member Q8 suitably perforated, and 'forming a part of the hub 16. Said cylindrical guide member acts as ai stop. to limit the extent ot opening oli the valve closures 25. Said valve closures are opened by the pressure oi' the heating liquid in the drier, and are positively closed by means ot a ca1n29. A spring 30 surrounds the valve stem` 2G ot each valve closurean'd: holdsthe parts tensioned so as to avoid noise and lostV motion. The cam. 29 opens the valve closures in rotation. It is essential that the cam be stationary, the hub 16 with the branch conduits and valve closures Vrevolving around it. The cam is therefore mounted upon a rod 81 which extends ksaid through the valve conduit 17 and fixed elbow 18, one end oit' said rod vbeing arranged in a socket 32 formed at the back ol.l said elbow. The rod is prevented from rotating by means ol" a pin 33 passing through a slot in the erd oil the rod 8 The hub 1G is :formed with an axial projection 3d, having a reduced end 35 which enters a recess in the cam, a'l'l'ording support for the latter. A spring 3G is compressively housed in a cap Si secured. to the socket 32 oi the elbow 18,

' spring bearing against the end ot the rod tor pushing said rod longitudinally and thus moving the cam into engagenn-rnt wi h the reduced end 35 of vthe projection 31e, the slot in said rod permitting this n'iovenient.

Aside trom the valve gear just described,r

the discharge connections are exactly the same as the i let connections, the liquid bei received from the hollow hub t gli the elbow 18 by the liquid return line 38, which conveys theliquid to pump 39. Said pun'ip 39 Forces the liquid thru the heater it) and bark thru the pipe connection if thru the drier again, thus keeping up a contiiuious circulation ot the heating liquid. Contini; ne; circulation is not, however, an e" iati..l lient/ure as theremight be some cases wi ere the liquid would be iorced thru the drier onlyv once and then used for sonic other purpose, or .disposed of as waste..

By. iiorining the inner shell 5 with a p'lu-k rality oil helices andi thus forming a corre spending number of spiral passages between the inner shell 5 and the outer shell 1 for the circulation of the heating liquid, not only will the apparatus be capable ot treating a greater quantity ot'material with-= in a givenV time, but it will also more eli'ectively and uniformly heat such material than would be the case it the inner shell .vere i provided with only a single continual helix to form a single continuous spiral passage between the inner and outer shells. This is because a plurality of internalv spiral threads on the inner shell 5 will cause the materiali to move from one end to the other of the apparatus more rapidly and theheating fluid will be; caused to pass more rapidly from one end to the other of the apparatus through each. of the plurality of spiral passages than would be the case it there was only a single vhelix and a single continuous spiral passage within the saine space. Further, since the heating fluid will move morel llO a single continuous spiral passage were prou vided, becauseuin the former case, there would be a plurality of comparatively short passages, whereasdn. thelatter. easeY there .s

fthe circular ytires .4lgand42 whichA roll on roller wheels 43 and 44, as is usually thecase..

WG111@ be a singlelong passage.

By -provf'ne whichl inlets` the heating liquid is permitted be the casefif thelqlld-.fwas supplied to all of said passages simultaneously,l because in the latter case, if the pressure.' of the' heat- Y .ing fluid be .low,-.it'might be disposed -to flow.

entirely. or at. amore rapidy rate Athrough one- .ofthepassagea or,i f the heating fluid be.

supplied under the properpressure'and one orinore .ofthe passagesbecomes partially obstructed, the heating liquid would -be dis-i posed to flow entirely or -more rapidly through that passage'or those. passages.

which offered the least'resistance to its flow. The drier= is supported by ,and rotateson with rotary driers. These roller wheels turn in bearings ,45 lsupported by or forming a part of the bed-plates46 and 47. These bed plates are in turn kSupported onthe foundation piers 48 and 49. Y

' Roller wheels 50 and 51 bear on the edges of the tire 4l and thus hold the drier in longitudinal alignment during rotation.

The entire outer surface of the drier eX- cept the surface in contact with the tires 41 and 42, and the driving gear 2 is heavily lagged with insulating material 52 to prevent as much as possible the loss of heat by radiation and convection'from the outer shell l. A shroud ring 53 is attached to the inlet end of the drier by welding or .other `suitable means. This ring acts as a receiving chamber for the material to be dried and feeds it to the helices as the drier revolves'.

Coal or other material to be dried enters thru the spout 54, and after being heated in the drier falls therefrom into the discharge hopper 55 from which'it passes to the discharge pipe 56. A hood 57 which is preferably continuous with the discharge hopper and surrounds the upper half ofthe exit end of the drier communicates with the vent Vor chimney 58 and serves as a means of ventilating yor carrying away the moisture driven off in the drier. 59 is a damperv at the base of the Ventilating stack tol regulate the amount of draft.

It is preferable to have a flared ring 60 attached by welding or other suitable means to the discharge endv of the drier to properly discharge the material passing thru the drier into the hopper 55.

The channels for the heating liquid are vented by valves 61to allow the escape of entrapped air when such channels are filled with the heating liquid and, when desired, to discharge any gases which may accumulate. A vent line 62 is also provided for the .each-pf the plurality q'f'. spiral. passages with` a separateinletthrough `rality of spiral passages for the Excessive pressure l inv the circulating system f isjprevented bythe relief valves 66 and 67,

by-pass 68 andpipe69, andalso bythe-vent line 62.

= While I have the above description disclosed what l believe to be a lpreferred'and practical embodimentv of.y my invention, it is to be understood thatv the specific details desGlibed are not limitative vin their in sofar as they'are expressly prescribed by theterms of the' appendedclaims.v

4HavingdescribedunyA invention what I claim as new and desirel to secure by Letters latent,is:y 'i .f.. v

l. A rotary drier including outer and inner shells, the inner shell having a plurality of internal and external spiral corrugations, said inner and outer shells forming between them a plurality of spiral passages for the flow of heating fluid and the internal corrugations of the inner shell serving to move material lengthwise thereof, said inner shell having at one end an inlet for the material to be treated and at its opposite end an outlet for said material.

2. A drier including outer and inner shells, the latter being provided with a plurality of parallel spiral corrugations, forming between the inner and outer shells a pluiiow of heating fluid, and means for supplying heating Huid in rotatio-n to said passages.

3.' A rotary drier including outer and inner shells, the latter being provided with a 'plurality of parallel spiral corrugations, forming between said outer and inner shells a plurality of passages for the ow of heating fluid, and means controlled by rotation of said drier for admitting heating fluid in rotation to said passages.

l 4. A rotary drier including outer and inner shells, the inner shell being provided with a plurality of spiral corrugations forming a plurality of spiral passages for the iiow of heating fluid, a conduit including a hub and axial portion, and branch conduits distributing fluid to said passages, a supply pipe, and a revoluble joint connectlng said supply pipe and axial portion.

5. A rotary drier including outer and Vin ner shells, the latter being provided with ing fluid, conduits arranged adjacent the ends of said drier including, respectively,

effect upon the. invention but merely illustrative except` inletlfand. discharge hubs and branch-fcone` duits; communicating with theV several pas# sages; means for supplying heating fluid to said: inlet huh, and. means controlled by ro= f tation of said drier' for permitting they flow of heated l-iquid in rotation through said Y and means operativezresponsively to 'rota--4 tion of sinddrier forfcdntrolling" the admis?- sion of! heating-fluid inrotati'on toy Said pas'- passages., l

6;v A rotary drier' including mea-ne for directing. the flow oit'v heated liquid thema-bout! in .definie separate1 passages,` and means controlled by rotation of said drier for admitting liquid in rotation; to said. passages.

7. A rotary drier including a plurality of .siral passages formed thereabout to direct t-e How of heating fluid, supply and discharge pipes, and conduits connected to said supply and discharge pipes, saidi conduits having passages communicating with said passages, valves controlling one set ofi branch conduits, and means operative respon sively by rotation of said? drier for controllingthel admission of heating fluid in rotation. to said passages 8. A rotary drier including` a plurality oi to direct the How of heaifin flui'dfsluppl-y and discharge pipes and con uits' connected thereto' ha-vingf branchen 'communicating fi-th' said passages, valves in onev of said lcon'- dnitsfcentrollng one setlol` branch conduits,

sages.- i 1 H92 A rotwrydier including a plurality of' parallel spi-rali passages formed thereaboui t@ direct! the How of heatingI Huid, supply and discharge pipeeand conduits sWi-Vel'ly con-neeedl theretohaifing branches communieating with said passages, valves in one" con duit con-trolling one set .ofI branch conduitelv and a stationary cani` for actuating said valves as the latt'er travel about said conduit re oneively toro'tation of said drier;

n testimony' whereof I havel hereuntoeet 45 

